Ignition system for burners



March l0, 1942.

IGNITION SYSTEM Filed March 25, 1941 A. sTocKsTRoM ET AL.'

FOR BURNERS 2 Sheets-Sheet l @aan wgauvmu y Cttornegs March 10, 1942. A,STOCKSTROM ET AL 2,275,998v

IGNITION SYSTEM FOR BURNERS Filed March 25, 1941 2 sheets-sheet 2Patented Mar. 1Q, 1942 l 2,275,993 iGNITioN SYSTEM Fon BURNERs ArthurStockstrom, Douglas D. Burnside, and Edwin H. Kahler, St. Louis, Mo.,assignors to American Stove Company, St. Louis, Mo., a corporation ofNew Jersey Application March 25, 1941, Serial No.` 385,128

21 Claims.

This invention relates to an ignition system and pertains primarily andspecifically to an electrical ignition system which has been conceivedand designed for use in connection with gas ranges, but the principle ofthe invention is applicable to other specific uses wherein it is desiredto electrically ignite a burner.

The primary object of the invention is the provision of a novel andhighly ecient electrical ignition system for gaseous fuel burners andparticularly burners of gas ranges.

Another object of the invention is the provision of an electricalignition system which is semi-automatic in operation. 1

A still further object of the invention is the provision of anelectrical ignition system having a timed cycle of operation and inwhich the timing of the cycle is accomplished by a circuit maker andbreaker of novel construction and operation.

Other specific objects, novel features of construction and improvedresults of the invention will appear from the following description andthe accompanying drawings in which an embodiment of the invention on agas stove is illustrated.

In the drawings:

Fig. l is a horizontal sectional view throughl a gas range having thepresent improved invention applied thereto.

Fig. 2 is a detail :fragmentary vertical sectional view through theflash tube, the pilot light burner and a portion of the main burner.

3 is a horizontal sectional view through the circuit maker and breakerwith the circuit open.

Fig. e is a horizontal sectional view through the circuit maker andbreaker with the circuit closed. Fig. 5 is a horizontal sectional viewthrough the circuit maker and breaker at the moment the circuit is aboutto be opened and the parts returned to the positions illustrated in Fig.3 of the drawings.

Referring now to the drawings, A designates a conventional insulatedrange oven and B an adjacent range compartment as is commonly found inranges now in use.

Gas from any suitable source is supplied to the main fuel manifold pipeI from which delivery is under the control of any conventional type ofgas valve 2 having exteriorly of the range body a manually operablevalve opening and closing handle 3.

The range here illustrated is provided with automatic oven heattemperature control which (Ci. 15S-117.1)

is effected by an oven heat regulator C the construction and operationAof which is unnecessary to describe inasmuch as thermostatic oventemperature control is now commonly found in ranges and can beaccomplished successfully and efliciently by any one of a number of ovenheat regulating systems which can be bought on the open market.Obviously thermostatic control of the oven temperature could beeliminated without departing from the spirit of the present invention.Exteriorly of the range body the oven heat regulator is provided with aset-v 5handle t and a temperature indicating a The oven temperatureregulator receives fuel from the gas cock through a pipe 6 and controlslgas is delivered into the main burner inlet manifold 8 by a jet ortting it. The safety valve is provided with a by-pass which when gas isdelivered to the safety valve permits a small portion thereof to pass tothe pilot light burner F through the tay-pass pipe i l.

By reference to 2 oi' the drawings it will i' be seen that the pilotlight burner is provided with a burner jet i2 which burns one or moreflames i3 which play upon and heat a thermal element M which issupported by and extends along the length of the pilot light burnerhousing. This thermal element when heated e'xpands and has an endextending into the housing portion I5 of the safety Valve and acts toopen said valve against its bias and permit gas to ow to the main burnerE.

The main burner E is provided with a plurality of main burner ports I 6and is additionally provided with a chain of burner ports Il whichextend toward the pilot light burner and when fuel is admitted to themain burner and escapes from the chain lighter ports I1 this fuel isignited by the flame 3 of the pilot burner, which flame is burning byreason of the pilot light having been already ignited in a manner whichwill hereinafter be described,v and upon being ignited burns as a seriesof flames I8 which perform the function of igniting the fuel which isescaping from the main burner ports I6 of the main burner E.

The pilot light burner jet is provided in its side with a burner orificeI8 aligned with the adjacent open end 20 of a flash tube G. This tube issupported upon the pilot light burner as indicated at 2| and is ofconsiderable length and extends outwardly therefrom and has a remoteopen end 22 across which extends an ignition coil 23 carried by a block24 which is properly apertured to telescopically receive the flash tube.Obviously the flash tube could be made of any desired shape in crosssectional configuration and the coil carrying block 24 will be composedo some suitable dielectric material.

The ignition coil 23 is connected in and forms a part of an electriccircuit the nature of which will now be described. Current is brought toa transformer 25 by a pair of lead-in wires 26 and 21 which can besuitably connected to the ordinary lighting circuit of the buildingwithin which theygrange is located. It is immaterial whether or not thecurrent supplied is alternating or direct in nature. From one side ofthe transformer a wire or conductor 28 is connected to a switch H theexact construction and operation of which will be hereinafter given.From the other side or the transformer a conductor 29 having therein aresistor 38 leads to and through a terminal bloeit 3i and from thisblock to and through the ignition coil and back through the block over awire 32 to the switch l-l. The switch H is provided with threeterminals. The wir@ 28 is connected to the switch terminal 33, the wire32 to the switch terminal 34, while a shunt wire 35 leading off of thewire 29 in front of the resistor is connected to the third switchterminal 36.

The switch or circuit maker and breaker H, as will be seen by referenceto Figs. 3 to 5 of the drawings, comprises a 'base 31 of suitabledielectric material within which are the aforementioned terminals 38, 34and 36. To this base is suitably secured a cover 38 to provide a closedhousing or chamber 39. This switch box is mounted `on or behind a frontpanel 48 of the range and is provided with a reciprocable push buttonvii the end of which is externally positioned in respect to the rangefor convenient operation.

To facilitate the mounting of the switch box we provide a bushing 42which extends through the range panel and in clamping the bushing to thepanel between the lock nuts 43 and 44 we position a soft resilientwasher 45 to prevent the panel, which ordinarily has an enameledexterior surface, from being chipped by reason of pressure exertedthereon by said lock washers.

The push button slides freely within they bushing and its inner endwithin the switch housing is provided with an enlarged head 4G.

Within the housing a spring lever 41 has an end suitably secured as at48 to the base block 31. This lever has an arm 49 having a normal biastoward the head of the push button so that it normally engages the same.as is illustrated in Fig. 3 of the drawings. The free end of this arm isbent backwardly upon itself as indicated at 50. The lever arm 49 carriesa supplemental spring arm I to the end of which is suitably secured anelectrical contact point or button 52. The spring lever 41 Viselectrically connected to the switch terminal post 33 as indicated at 53and accordingly the electrical contact 52 is electrically connected tothe current conducting wire 28.

Centrally of the housing a contact point or button 58 is arranged inapproximate alignment with the contact button 52 and is carried on theend of athreaded bolt 51 which is electrically connected to the currentconducting wire 32 through the switch terminal post 34. The threadedbolt 51 provides for adjustment of the contact button 55 toward and awayfrom the contact button 52.

A second spring lever 58 has one end suitably anchored as at 59 to theswitch base block 31 and has an arm 60 bent slightly back upon itself toprovide an end arm 6| which is disposed at an inclination. This springlever 58 has a bias in the direction indicated by arrow which is towardthe center of the switch housing with the result that when the switchbutton 4I is ln its extended position the arm 6| of the lever 58slightly overlies the arm 50 of the lever 41 and holds the arm 49 of thelever 41 in engagement with the head of the push button and with theelectrical contact button 52 in separated relationship in respect to theadjustable contact button 55.

The spring lever 58 is bi-metallic in nature so as to constitute athermally responsive element which upon being heated bows or moves intothe opposite direction to its normal tension or bias or into theposition illustrated in Fig. 5 of the drawings.

lA resistance coil 62 is coiled about a portion of the 'oi-metallicspring lever 38 and electrically interconnects the current conductingwires 34 and 35 by having its ends electrically connected to the switchterminal posts 34 and 36 respectively.

It will be noted that the circuit is such as to be in parallel asrespects the ignition coil and the resistance heater in the switch. Withthe resistor 30 in the circuit to the ignition coil less current isdelivered to the ignition coil than to the resistance heater in theswitch. Should it be found desirable however the circuit could bearranged in series.

A few words should suffice to an understanding of the operation oftheinvention. When the manual fuel valve 3 is opened fuel flows through theheat regulator to the safety valve and through the bypass thereof to theburner orifices of the pilot light burner. The range operator thenmanually pushes in upon the switch plunger 4l which brings the contactpoints 52 and 56 into engagement and the parts are locked in thisposition as illustrated in Fig. 4 of the drawings.

The electric circuit is now closed through both the ignition coil at theflash tube and also through the heating coil 62 in the switch. Gas isbeing discharged by the pilot light burner into the flash tube and thisupon meeting the hot ignition coil explodes and flashes back and ignitesthe pilot burner. After a short time duration the heat from this burnercauses the thermal element I4 to expand which results in an opening ofthe safety valve D which permits gas to iiow to the main burner. Thisgas issues from the chain lighter ports as well as the main ports of themain burner. The chain lighter ports are first ignited by the flame ofthe pilot burner and the flames burned by the chain lighter ports causethe ignition of the gas issuing from the main burner ports. Throughoutthis cycle of operation the switch heater 62 has been heating thebi-metallic arm or lever 58 and shortly after the main burner becomesignited this heat has caused the bi-metallic arm of the switch to warpor move sufficiently to' cause its arm 60 to clear engagement with thecontact carrying arm 49, as is illustrated in Fig. of the drawings, and

. permit the arm 49 under its tension to move outwardly, pushing thepush button 4I beforec it, and to assume a position where the contacts52 and 56 become separated. The circuit is then broken and the parts arein the positions illustrated in Fig. 3 of the drawings where it will beseen that the arm El oi the bi-metallic lever 5B prevents any accidentalinward movement of the switch push button and thus guards against thecircuit being accidentally closed.

The length of the cycle of time the circuit remains closed after beingmanually closed can be adjusted to meet the particular situation. Thiscan be accomplished by using a bi-metallic arm or lever 58 which willdeflect a larger or greater amount in accord with the heat appliedthereto on a time basis or it can be varied by varying the heat outputof the heating coil 62. It can also be varied by reducing or increasingthe amount of overlap of the arms 49 and 6@ which will incease ordecrease the amount of deilection required of the bi-metallic arm inmovingr to an unlatched 4 position.

The switch is such as to have the desirable feature of providingapproximate uniform contact pressure between the contact points 52 and55. This is by reason of the fact that the contact carrying arm 5| has abias toward the xed contact 5E so that when the contacts are broughtinto engagement the pressure between them re mains practically constantnotwithstanding the fact that the release or unlatching of the lever 49is gradual until the end of its movement.

The switch also has the desirable feature that when the contact is nallybroken it is by a snapaction because once the arm 60 of the bi-metalliclever 53 reaches a point where it is clear of the arm t9 this armsprings away towards its normal position carrying with it the contact52. It will be seen too that as the switch is closed the arrangement ofparts are such that it will snap to a closed position.

The switch cover 38 assures that the contact points and other operatingparts of the switch are guarded against dirt and injury.

The invention-is to be limited only within the scope of the hereinafterappended claims.

We claim:

1.1An ignition system for a gas range or the like comprising, a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, a normally closed safety valve stopping the ow of fuel tothe main burner from said manually operable valve, a thermo responsivemember operable by the heat generated by said pilot burner to open saidsafety valve, an open electric circuit includingan electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch'by which said circuit can be closed, said switch including afixed contact and a movable contact biased away from said fixed contact,means to move said contacts into engagement, a resilient lock armautomatically latching said contacts in engagement upon their being sopositioned, said lock arm having a portion composed of thermo responsivematerial, an electric heater arranged inheating relationship to thethermo responsive portion of said lock arm, said heater being in saidcircuit, and said heater ywhen said circuit is closed acting after apredetermined time duration to cause said lock arm to move into anunlatched position, for the purpose described.

2. An ignition system for a gas range or the like' comprising, a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, a normally closed valve stopping the iow of fuel to themain burner from said manually operable valve, a thermo responsivemember operable by the heat generated by said pilot burner to open saidsafety valve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch by which said circuit can be closed, said switch including afixed contact and a movable contact carried by a resilient arm having abias which maintains said contacts in separated relationship, a movableswitch lever for moving said contacts into engagement, a resilient lockarm resiliently engaging said movable contact carrying arm and holdingsaid arm in engagement with said movable switch lever, said lock armmoving beneath said movable contact carrying arm and holding the sameagainst movement when said contacts are brought into engagement, saidlock arm being thermally responsive, an electric heating coil in heatingrelationship with said lock arm and being in said electric circuit, andupon said electric circuit being closed said heater acting after apredetermined time to cause said loci: arm to move out of engagementwithsaid movable contact carrying arm to permit said arm `to respond toits normal tension to move its contact away from said xed contact.

3. An' ignition system for a gas range or the like comprising, a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, a normally closed valve stopping the iiow of fuel to themain lburner from said manually operable valve, a thermo responsivemember operable by the heat generated by said pilot burner to open saidsafety valve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch by which said circuit can be closed, said switch including aiixed elecirical contact, a spring arm in separated relationship to saidxed contact and havinga bias in a direction away from said contact,a`second resilient arm carried by said rst named arm and having anelectrical contact in said circuit, said second spring arm biasedtowards said fixed contact but normally in separated relation thereto,means to move said arms to bring said contacts into engagement, aresilient lock arm having a thermo responsive portion, said lock armengaging said first named arm and locking the same against movement whenthe contacts have been brought into engagement, an electric heater inheating relationship to the thermo responsive portion of said lock armand being in said electric circuit, and said electric heater actingafter said circuit has been closed for a predetermined time to causesaid lock arm to disengage said rst named arm to permit said circuit tobe broken in response to the movement under the normal ten'- sion ofsaid iirst named arm.

4. An ignition system for a gas range or the like comprising a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, a normally closed valve,

stopping the flow of fuel to the main burner from said manually operablevalve, a thermo responsive member operable by the heat generated by saidpilot burner to open said safety valve, an open electric circuitincluding an electric igniter in lighting relationship to the fuelissuing from said pilotburner, a switch by which said circuit can beclosed, ysaid switch including a fixed electrical contact, a resilientmovable arm carrying an electrical contact, the bias of said arm holdingsaidcontacts out of engagement, a resilient lock arm normally engagingsaid contact carrying arm and resiliently preventing movement of saidarm to bring said contact into engagement, means to apply pressure tosaid contact carrying arm to move the same past said lock arm to causesaid contacts to engage, the bias of said lock arm being such as to movesaid arm beneath said movable contact carrying arm to lock the sameagainst movement when said contacts are in engagement, said lock armbeing in the nature of a thermo responsive member movable to an unlockedposition in respect to said contact carrying arm when heat is applied,an electric heater in heating relationship to said lock arm, said heaterbeing in said electric circuit, and said electric circuit being closedto said heater when said contacts are brought into engagement.

5. A construction such as deiined in claim 4 wherein, said thermoresponsive lock arm is constructed to compensate against movement inresponse to ambient heat from said range.

6. A construction such as defined in claim, i wherein, said electricigniter and said lock arm heater are connected in parallel in saidcircuit, and a resistor is in the circuit to said electric igniter.

7. An ignition system for a gas range or the like comprising a mainburner, a pilot burner for igniting said main burner,a manually operablevalve for initially controlling the supply of fuel to both of saidburners, a normally closed valve stopping the iiow of fuel to the mainburner from said manually operable valve, a thermo responsive memberoperable by the heat generated by said pilot burner to open said safetyvalve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch by which said circuit can be closed, said switch including afixed contact and a movable contact biased away from said fixed contact,means to move said contactsv into engagement, a lock member acting toautomatically latch said contacts in engagement with one another aftertheir having. been so positloned, said lock member being thermoresponsive, a heater arranged in' heating relationship to said lockmember, said heater being automatically brought into operation when saidcircuit is y closed, and said lock member after-a predetermined timeinterval respondingtothe .heat generated by said heater andautomatically moving into an unlatched position in respect to saidmovable contact.

8. An ignition system for a gas range orthe like comprising, a mainburner, a pilot burner for igniting said main burner, a manually oper-:Y able valve for initially controlling the supply of fuel to both ofsaid burners, a normally-closed valve stopping the flow of fuel to themain burner from said manually operable valve, a thermo responsivemember operable by the heat generated by said pilot burner to open saidsafety valve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch by which said circuit can be closed, said switch including afixed elett-.1 trical contact, a spring arm in separated rela?,1

tionship to said fixed contact and having a bias in a direction awayfrom said contact, a second resilient arm carried by said first namedarm and having an electrical contact in said circuit, said second springarm biased towards said xed contact but normally in separated relationthereto, means to move said arms to bring said contacts into engagement,a resilient lock arm having a thermo responsive portion, said lock armengaging 'said first named arm and locking the same against movementwhenA the contacts have been brought into engagement, a heater inheating relationship to the thermo responsive portion of .said lock arm,said heater being automatically brought into operation upon the closingof said circuit, and said heater acting after said circuit has beenclosed for a predetermined time to cause said lock arm to disengage saidfirst named arm to permit said circuit to be broken in response to themovement imparted to said first named arm due to the bias thereof. f

9. An ignition system for a gas range or the like comprising a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, a normally closed valve stopping the flow of fuel to themain burner from said manually operable valve, a thermo responsivemember operable by the heat generated by said pilot burner to open saidsafety valve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from V said pilot burner, aswitch by which said circuit can be closed. said switch including afixed electrical contact, a resilient movable arm carrying an electricalcontact, the bias of said arm holding said contacts out of engagement, aresilient lock arm normally engaging said contact carrying arm andresiliently preventing movement of said arm to bring said contact intoengagement, means to apply pressure to said contact carrying arm to movethe same past said lock arm to cause said contacts to engage, the biasof said lock arm being such as to move said arm beneath said contactcarrying arm to lock the same against movement when said contacts are inengagement, said lock arm being in the nature of a thermo responsivemember movable to an unlocked position in respect to said contactcarrying arm when heat is applied, a heater in heating relationship tosaid lock arm, and said heater being automatically brought intooperation upon the closing of said electric circuit. 10. A constructionsuch as defined in claim 2 wherein said electric heater isin the form ofa coil coiled about said thermo-responsive lock arm. '11. In an ignitionsystem for a gas range or the like, Aa. main burner, a pilot burner forigniting saidmain burner, a, valve for initially controlling the supplyo! fuel to both of said burners, a normally closed safety valve forstopping the flow of fuel to the main burner from said first namedvalve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, athermo-responsive -member operable by the heat generated by said pilotburner to open saidsafety valve, a @witch :by which said circuit can beclosed, and means causing said switch to automatically open after saidelectric circuit has been closed for a predetermined length of time. 412. In an ignition system for a gas range or the like, a mainburner, apilot burner for igniting said main burner, a valve for initiallycontrolling the supply of fuel to both of said burners, a normallyclosed safety valve for stopping the flow of fuel to the main burnerfrom said first named valve, an open electric circuit including anelectric igniter in lighting relationship to the fuel issuing from saidpilot burner, a thermoresponsive member operable by the heat generatedby said `pilot burner to open said safety valve, a switch by which saidcircuit can beclosed, and means brought into operation by the closing isaid electric circuit causing said switch to auto matically open aftersaid electric circuit has been closed for a predetermined length oftime.

13. An ignition system for a gas range or the .like comprising a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel to both ofsaid burners, anormally closed valve stopping the iiow of iuel to themain burner from manually operable valve, a thermo-responsive memberoperable by the heat generated by said pilot burner open electriccircuit including an electric igniter in lighting relationship to thefuel issuing from said pilot burner, a switch by which said circuit canbe closed, said switch including a fixed conto open said safety valve,'an

tact and a movable contact biased away from l said fixed contact, means.to Amove said contacts into engagement, a lock member acting toautomatically latch said contacts in engagement with one another aftertheir having been so positioned, thermo-responsive means for moving saidlock member to an unlatched position, a heater arranged in heatingrelationship to said lock operating thermo-responsive means, and saidheater being automatically brought into operation when said circuit isclosed and the heat generated thereby causing said lock member to bemoved into an unlatched position in respect to said movable contactafter a predetermined time in.- terval.

14. A construction such as defined claim 13 wherein, saidthermo-responsive lock operating means is constructed to compensateagainst movement in response to ambient heat from said range.

15. A construction such as deilned in claim 13 wherein, said heater isan electric heater and is in the form of a coil coiled about said lockoperating thermo-responsive means.

16. An ignition system for a gas range or the like comprising, a mainburner, a pilot burner for igniting said main burner, a manuallyoperable valve for initially controlling the supply of fuel sive memberoperable by the heat generated by said pilot burner to open said safetyvalve, an open electric circuit including an electric igniter inlighting relationship to the fuel issuing from said pilot burner, aswitch by which said circuit can be closed, said switch including afixed contact and a contact carried by a movable ar-m which is biased tomaintain said contacts in separated relationship, means for moving said,contacts into engagement, a lock arm biased to engage said movablecontact carrying arm to hold the same against movement when saidcontacts are brought into engagement, thermo-responsive means for movingsaid lock arm against its bias, a heater for heating saidthermo-responsive means and being brought into operation when saidelectric circuit is closed, and the heat generated by said heater actingafter a predetermined time cause said thermo-responsive means to movesaid lock. arm out of engagement with said movable contac" carrying armto permit said arm to move its contact away from said xed Contact.

l'l. A construction such as defined in claim 7 wherein, saidthermo-responsive lock member is constructed to compensate againstmovement in response to ambient heat from said range.

18. A construction such as defined in claim 7 wherein,`said heater is anelectric heater arranged in said electric circuit, and said electricigniter and said electric heater are connected in parallel in saidcircuit.

19. A construction such as deiined in claim 12 wherein, the meanscausing the opening of the switch is thermo-responsive in nature and iscaused to actuate by the heat from a heater brought into operation bythe closing of said electric circuit.

20. A construction such as defined in claim 12 wherein, the meanscausing-the opening of said switch is a thermo-responsive means, and anelectric heater is provided in said electric circuit for generating the.heat for causing the operation of said thermo-responsive means aftersaid circuit has been closed for a predetermined length oi.' time.

2l. A construction such as deined in claim 12 wherein, the means causingsaid switch to automatically open is a thermo-responsive means, anelectric heater in said electric circuit, and said heater being in theform oi a coil coiled about said thermo-responsive means to heat thesame to cause the operation thereof after a predeterto both of saidburners, a normally closed valve stopping the flow of fuel to the mainburner from said manually operable valve, a thermo-responf mined lengthof time.

ARTHUR STOCKSTROM. DOUGLAS D. BURNSIDL. EDWIN H. KAI-ILER.

